Sinusitis is an infection (usually bacterial) of one or more of the sinuses. In general, it occurs more commonly in adults than in children.

The sinuses are air-filled cavities located within the facial bone structure and connected to the nose. There are four major groups of sinuses: frontal, ethmoidal, sphenoidal, and maxillary.

The sinuses are lined with a mucous membrane and are normally kept clear when mucus drains through them into the nasal passages. If the sinuses are obstructed, normal drainage cannot occur, and infection can result.

Complications

It is rare but possible for long-lasting sinusitis to lead to more serious disorders. For example, a persistent infection of the sinuses can travel to the brain, causing meningitis (inflammation of the membranes covering the brain and the spinal cord), or to the bone, resulting in osteomyelitis (inflammation of a bone).

Causes

A sinus infection may be triggered by anything that prevents the mucus in the sinuses from draining properly into the nasal passages. Possible causes include swimming and diving, injury to the sinuses or to other structures in the facial area, abnormal structure of the facial bones, allergies, or an abscess (inflamed pocket of pus) in a tooth, which may penetrate the sinuses and allow bacteria to enter them. Many different types of bacteria can also cause sinusitis, including some of the same strains that lead to pneumonia, laryngitis, and middle ear infections.

Symptoms

Sinusitis is characterized by pain and tenderness above the infected sinus, which is felt in the face and forehead, behind the eyes, in the eyes, near the upper part of the nose, and even in the upper teeth. This facial pain may be accompanied by headache, slight fever, chills, sore throat, and a discharge of pus from the nose.

Sinusitis usually lasts about two weeks, with the pain often subsiding in the morning and worsening as the day goes on. The pain tends to fluctuate as the patient moves and changes positions, especially when bending forward at the waist.

Diagnosis

The sinuses cannot be seen directly by a doctor, so diagnostic evaluation may include an X-ray examination to check for the presence of fluid or abnormalities in the sinuses and to determine which of the sinuses are infected. Computed tomography is an excellent tool for evaluating serious sinus problems.

Treatment

Sinusitis is treated by encouraging drainage of the sinuses. Nasal decongestants and moist heat work to aid sinus drainage. The doctor will usually prescribe an antibiotic that will kill the bacteria that most commonly trigger sinusitis.

If these treatments bring no relief, the doctor may perform a sinus puncture to determine exactly which bacteria are present. In this procedure, a needle is inserted into the sinus, and a sample of the fluid is removed. (This is necessary because the discharge coming from the nose may contain bacteria that are different from those infecting the sinuses.) On the basis of analysis of the fluid sample, a more specific antibiotic may be prescribed.

In severe cases of sinusitis, codeine (a narcotic painkiller) may be prescribed to dull the pain, and the doctor may clear the sinuses by injecting a solution through the nose to flush out the sinus cavities.

In some cases, surgery may be necessary to remove a nasal polyp (a mass of swollen tissue), repair abnormal bone structures, or remove infected sinus tissue.

Prevention

There is some evidence that smokers are more likely to suffer from sinusitis than are nonsmokers. Those who frequently have colds are also more susceptible to sinusitis. Avoiding smoking and exposure to persons with colds may help to prevent sinusitis.